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6.7: Exercise 2 - Identifying strains by nutritional requirements

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    Your team will be given three strains, each of which carries a different met mutation. Pre- pare spot plates (Chapter 4) to distinguish between the three strains. Each member of the team should prepare serial dilutions of a single strain.

    1. Spot your dilution series on each of the plates that your team received. Spot the complete di- lution on one plate before proceding to the second plate. Use the same pattern of strains/rows on each of the different selective plates. Make sure that the plates are properly labeled!
    2. Incubate the plates at 30 oC until colonies should become apparent. Note that some colonies grow slowly on defined media and may require more than 3 days to appear. When colonies reach the desired size, transfer the plates to the cold room for storage.
    3. Scan the plates as you did in Chapter 4 to record your data. These data will become the focus of your first lab report for the semester. Think of how you would like your figure to look as you place the plates on the scanner.
    • Scan the plates containing variations of YC media together, taking care to orient the plates

      in the same direction.

    • Scan the plate containing BiGGY agar separately using the color settings.

    4. Use the predictions from the previous exercise to identify your team’s mutant strains. This information will be compiled into a table in your lab report.

    Consult the “Write It Up!” chapter for instructions on preparing lab reports.

    6.7: Exercise 2 - Identifying strains by nutritional requirements is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

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